Circular knitted web and method for its manufacture



0st. 15, 1940. v. w. MEHNERT 2,237,915

JIRCULAR KNITTED WEB AND METHOD FOR ITS MANUFACTURE Filed Nov. 30, 193v2 Sheets-Shes}. 1

Val/(Mt- Malta? NEH/YER? Oct. 15, 1940- v. w. MEHNERT 29 3 5 CIRCULARKNITTED WEB AND METHOD FOR- ITS MANUFACTURE Filed Nov. 30, 1937 2Sheets-Sheet 2 Awe/Mar: mm": Walter Ira/year & W24

Patented Oct. 15, 1940 UNITED STATES CIRCcaAR KNITTED WEB AND METHOD FoRITS MANUFACTURE Volkhart Walter Mehnert,

Siegmar- Schonau,

Germa'ny, assignor to the firm Elite-Diamantwerke Aktiengesellschaft,

Siegmar- Schonau,

Germany, a company of Germany Application November 30, 1937, Serial No.177,369 In Germany December 1, 1936 9 Claims.

The invention relates to a circular knitted web as is intended inparticular for use as lining or cover material for friction couplings,e. g. in automobiles. In that connection it is important '5, that theknitted web be elastic and porous in order to receive the saturating orimpregnating material, 'e. g. resin, artificial resin or similarproducts known as brake Coverings or linings and that the fibrousmaterial withstands the abrasive eifect of lo the frictional stresswithout becoming frayed or unravelled.

In order to Comply with these conditions in the best manner possible,keeping at the same time the consumption of asbestos yarn or threadscom- 15 paratively low, the invention provides the knitting of the ringas a fiat strip or band of circular shape. In it the meshes or stitchesare to be produced in radial rows so that their loops are directed atright angles to the radius',-i. e. tangentially, and, in order to obtaina uniform circular shape, each outer mesh of a row is larger than theadjacent one situated more towards-the centre of the same row.

The circular band fashioned in this manner is joined together at itsends, e. g. by sewing up.

All according as to Whether the band had the full length of a circularring or only the length of a segment of a circular ring there resultsafter the joining together either a fiat circular ring or the 30 surfaceof a truncated cone. In order to obtain plane and uniform circular ringsthe relative size of the loops shall be in direct proportion to thedistance of the mesh from the centre of the Circular ring.

A further object of the invention consists in the method formanufacturing the said knitted web on a flat knitting machine.

The method is characterized in that the loops, during the knitting ofeach row of meshes, are increased in one direction of knitting andcorrespondingly decreased in the other direction of knitting. For thepurpose of accomplishing this mode of operation every following needlein the 'row of meshes is drawn back farther than the preceding needle bythe amount of the intended increase of the size of the loops.

This method can be attained in a flat knitting machine where the drawingback part of the cam box causing the formation of the loops is providedwith a device which, during the stroke of the carriage, displaces thatpart in the direction of the stroke of the needle. The same result can,

' however, be achieved in a machine with a fixed drawing back part ifthe drawing back length of the needles working side by side differs. bythe amount of the size of, the loops, e. g. by a different distancebetween the heel and the head of each individual needle.

Since the loops of that kind of knitting according to the invention arelarger at the outer rim of the circular ring than the inner loops, theyare, consequently knitted more loosely than the inner ones. This byitself complies with the conditions for the transmission pfthe twistingor turning moment through the coupling covering, as the lever arm of theforces to be transmitted is longer towards the periphery than towardsthe centre. Yet it may be of advantage to render closer the outerstitches of the knitted webf This may be accomplished in that way thatthe outer loops are knitted with yet an additional thinner thread. Theuniform thickness of the knitted material across the whole width can beachieved in this manner that the band is conducted through a pair ofrollers in which the knitted material is pressed and made closer.

After the pressing, or even immediately before it, the knitted materialmay be saturated or impregnated with resins, artificial resins, e. g.condensation products of phenol formaldehyde, or other substances knownas brake material. After the impregnation the ring may also be smoothedby grinding. I

A particularly suitable kind of closely knitted fabric whichwill notfray even under great stress through frictional forces, isthe so-calledinterlock-knitted fabric. It is understood that the terminterlock-knitted fabric used in the specification and claims hasreference to a fabric in which the loop courses of a plurality of layersarranged upon each other are formed by a continuous thread, the loops ineach course being ar- I cover rin Fig. 3 a top plan View of a knittedstrip of fabric having the form of a full plane circular ring, theadjacent ends of said strip being not yet connected with each other,

Fig. 4 a cross-sectional view of the strip of fabric taken on line 4-4of Fig. 3,

Fig. 5 a cover ring in the shape of a truncated cone,

Fig. 6 a top plan view of a knitted strip of fabric of the length of asegment of a circular ring, by

means of which the truncated cone according to Fig. 5 is formed,

Fig. 7 a top view of a part of a kniting machine with the cam box bymeans of which the ring is manufactured,

Fig. 8 another arrangement of the knitting needles in a machine formanufacturing the ring,

Fig. 9 a modified embodiment of the ring with reinforced rim part whilebeing manufactured,

Fig. 10 a roller device for compressing the ring.

A coupling flange according to Fig. 1 consists of the knitted rings lsaturated with resins, these rings being fastened in any desired way ona metal disc 2, e. g. by means of hollow rivets 2. The disc sits withits hub 3 on the driving or driven shaft 4 and is non-rotatablyconnected with the latter by means of the wedge 5.

Preferably, the above mentioned knitted ring I is made of a so-calledinterlock-knitted fabric as diagrammatically shown inFig. 2. In thisembodiment the interlock-knitted fabric has two layers arranged uponeach other. The upper layer has the loops 6, the lower layer has theloops 6. The loop courses of both layers are formed by the samecontinuous thread, which,

one back and forth movement of the thread between the outer and innercircumferences of the ring taken in consideration, at first forms afirst loop in the lower layer, then forms a first loop in the upperlayer out of line with said loop of the lower layer, then forms a secondloop in the lower layer spaced from the first loop of the lower layer,then forms a second loop in the upper layer spaced from the first loopof the upper layer, etc., whereupon, during the return movement of thethread from the inner circumference to the outer circumference of thering, the thread forms alternate loops in the same alternate manner inthe layers, said alternate loops being positioned in the spaces betweenthe loops formed during the first mentioned movement of the thread fromthe outer circumference to the inner circumference of the ring. Thus,the two layers of the knitted fabric are interlocked with' each other.The loop courses 1 of both layers extend in radial direction. The lengthof the loops of each loop course gradually increases from the innerselvage of the fabric to the outer selvage thereof, and the length ofevery loop is in direct proportion to the distance of the loop from thecentre 9 of the circular fabric. Of course, any other type ofweftknitted fabric having loops formed of a contin-' As best shown inFigs. 3 and 4 the curved strip 50 of knitted fabric used for themanufacture of a ring-like clutch lining has such a length, that itforms a plane circular ring when its ends I0 and ID are placed adjacentto each other. When the ends l0 and ID of the plane circular strip arebrought together, they are connected with each other bya seam II asshown in Fig. 2. Then the ring-like clutch lining thus obtained may beimpregnated with a binding agent, if desired.

If it is desired to produce a lining of the form of a frusto-conicalmember as shown in Fig. 5, a strip l2 of a curved knitted fabric isused, which has only the length of a segment of a circular ring as shownin Fig. 6. The ends [5 and I5 of the strip l2 are brought together andare connected with each other by a seam or the like. The upper edge [3of the frusto-conical member has a smaller diameter than the lower edgeMl. The shape of the frusto-conical member depends on the length of thestrip I2 in proportion to the radius 8.

As may be gathered from Fig. 2,'the knitted web consists of a thread I6, preferably of asbestos, which is twisted of several individualthreads ll. Each one of the individual threads I! may possess a metalcore l8, e. g. of brass wire.

For the manufacture of the band on the flat knitting machine thearrangement of Fig. 7 is put into practice. The carriage 20 is laterallydisplaceable on the needle bed IS. The cams 2i and 2| of the cam box areguided with their feet 23 and 23, by way of a system of rods 22 and 22,in a curved groove or path 24, which is situated at the needle bed [9and is formed by the sliding cams 25. 'During the movement of thecarriage 20 in the direction of the arrow A the foot 23, together withthe cam 2|, is displaced upwards, at right angles to the direction ofthe carriage stroke, by the distance 26 corresponding to the inclinationof the incline 24. In accordance with this the loops of each row ofmeshes being produced one after the other, are reduced. In one directionof the carriage; i. e. in the direction opposite to that of the arrow A,the size of the loops is correspondingly increased by the cam 2| laggingduring this stroke, this cam being controlled by means of the guidingrod 22' and foot 23'. The cams 2| and 2| are reversed or changed in theusual manner with each change of direction of the carriage. The slidingcam 25 can be pivoted around the axis 25 whereby the 29 differs alwaysby the intended distance 26 in the size of the loops, so that also inthis manner the size of the loops increases in one direction anddecreases in the other direction.

The parts of the rim in which the loops are worked loosest can bereinforced in the manner illustrated by Fig. 9, in order to obtain acloser knitted web. The loops So, being situated nearest to the outercircumference, are formed, or reinforced respectively, apart from thethread I 6, also by an additional thinner thread 30; the in ner loops 6bare formed solely by' the thread [6. The yarn guide 3| passes the entirewidth of the band, whereas the yarn guide 32 feeding the additionalthread 30, passes only the width of the outer loops 6a.

In order to obtain a uniform thickness and good compactness of the ring,the same is conducted through a pair of rollers, either before or afterbeing impregnated. As best shown in Fig. 10, the rollers 33 have aconical form. They can be driven jointly by means of bevel gear wheels34 less specific as. to structural features, it is to be understood thatthe invention is not limited to the specific features or purposes shownand described.

Having now particularly described and ascertained .the' nature of mysaid invention andin what manner the same is to be performed, I dc,-clare that what I claim is:

What I claim is:

- l. A method of manufacturing clutch linings or the like, comprisingthesteps of knitting a curved strip of fabric of a length adapted to form aplane circular ring when the ends of the strip are placed adjacent toeach other, and connecting the ends of said strip with each other toform a plane circularlring.

2. A method of manufacturing clutch linings or tne like, comprising thesteps of knitting a curved flat strip of fabric of a length adapted toform a. plane circular ring when the ends of the strip are placedadjacent to each other, compressing said strip, impregnating said stripwith a binding agent, and connecting the ends of said flat strip witheach other to form a plane circular vage of the strip to the otherselvage thereof and gradually decreasing the length of the loops fromthe latter selvage to said. first mentioned selvage during the knittingof consecutive loop courses for the formation of a strip of curvedshape, making the strip of a length adapted to form a plane circularring when the ends of the strip are placed adjacent to each other, andconnecting the ends of said strip with each other to form a planecircular ring.

4. As a.v new article of manufacture, a weftknitted fabric forming aplane circularring having loops formed of a continuous thread and havingradially extending loop courses, the length of the loops of each loopcourse gradually increasing from the inner selvage of the fabric to theouter selvage thereof.

' 5. A new article of manufacture of the circular wefteknitted fabric asclaimed in claim 4, in which thelength of every loop is in directproportion to the distance of the loop from the centre of the circularfabric.

6. As a new article of manufacture, a weftknitted interlock-fabricforming a plane circular ring having loops formed of a continuous threadand having radially extending loop courses, the length of the loops ofeach loop course gradually increasing from the inner selvage of thefabric to the outer selvage thereof, the loops being formed of asbestosthreads containing at least one thin metal wire, and the frabic beingimpregnated with a binding agent and being pressed flat.

. '7. A new article of manufacture as claimed in claim 6, in which thelength of every loop of. the circular weft-knitted fabric is in directproportion to the distance of the loop from the centre of the circularfabric.

8.-A new article of manufacture as claimed in claim 4, in which thecircular ring consists of an interlock knitted fabric.

9. A new article of manufacture as claimed in claim 4', in which theloops are formed of asbestos threads containing at least one thin metalwire.

VOLKHART WALTER MEHNERT.

